Evaluation of wall slip effects on the flow characteristics of petroleum coke-water slurry flow along pipelines

2017 ◽  
Vol 12 (5) ◽  
pp. 818-826
Author(s):  
Xiaobin Zhang ◽  
Meng Liu ◽  
Kagiso Bikane ◽  
Yanrong Li
Keyword(s):  
Petroleum Coke ◽  
Flow Characteristics ◽  
Wall Slip ◽  
Slurry Flow ◽  
Water Slurry ◽  
Slip Effects

Speeding up thermocapillary migration of a confined bubble by wall slip

2014 ◽  
Vol 746 ◽  
pp. 31-52 ◽  
Author(s):  
Ying-Chih Liao ◽  
Yen-Ching Li ◽  
Yu-Chih Chang ◽  
Chih-Yung Huang ◽  
Hsien-Hung Wei
Keyword(s):  
Film Thickness ◽  
Slip Length ◽  
Flow Characteristics ◽  
Wall Slip ◽  
Fluid Viscosity ◽  
Tube Radius ◽  
Thermocapillary Migration ◽  
Slip Regime ◽  
Slip Effects ◽  
Slight Discrepancy

AbstractIt is usually believed that wall slip contributes small effects to macroscopic flow characteristics. Here we demonstrate that this is not the case for the thermocapillary migration of a long bubble in a slippery tube. We show that a fraction of the wall slip, with the slip length $\lambda $ much smaller than the tube radius $R$, can make the bubble migrate much faster than without wall slip. This speedup effect occurs in the strong-slip regime where the film thickness $b$ is smaller than $\lambda $ when the Marangoni number $S= \tau _{T} R/\sigma _{0}~ (\ll 1)$ is below the critical value $S^* \sim (\lambda /R)^{1/2}$, where $\tau _{T}$ is the driving thermal stress and $\sigma _{0}$ is the surface tension. The resulting bubble migration speed is found to be $U_{b} \sim (\sigma _{0}/\mu )S^{3}(\lambda /R)$, which can be more than a hundred times faster than the no-slip result $U_{b} \sim (\sigma _{0}/\mu )S^{5}$ (Wilson, J. Eng. Math., vol. 29, 1995, pp. 205–217; Mazouchi & Homsy, Phys. Fluids, vol. 12, 2000, pp. 542–549), with $\mu $ being the fluid viscosity. The change from the fifth power law to the cubic one also indicates a transition from the no-slip state to the strong-slip state, albeit the film thickness always scales as $b\sim RS^{2}$. The formal lubrication analysis and numerical results confirm the above findings. Our results in different slip regimes are shown to be equivalent to those for the Bretherton problem (Liao, Li & Wei, Phys. Rev. Lett., vol. 111, 2013, 136001). Extension to polygonal tubes and connection to experiments are also made. It is found that the slight discrepancy between experiment (Lajeunesse & Homsy, Phys. Fluids, vol. 15, 2003, pp. 308–314) and theory (Mazouchi & Homsy, Phys. Fluids, vol. 13, 2001, pp. 1594–1600) can be interpreted by including wall slip effects.

Slurry flow characteristics numerically analysed using sand water mixture

2021 ◽  
Author(s):  
Varinder Singh ◽  
Satish Kumar ◽  
Dwarikanath Ratha
Keyword(s):  
Flow Characteristics ◽  
Water Mixture ◽  
Slurry Flow

scholarly journals Heat Transfer and Slip Effects on the Mhd Peristaltic Flow of Viscous Fluid in A Tapered Microvessels: Application of Blood Flow Research

2019 ◽  
Vol 9 (1) ◽  
pp. 5384-5390
Keyword(s):  
Heat Transfer ◽  
Blood Flow ◽  
Research Work ◽  
Flow Characteristics ◽  
Peristaltic Flow ◽  
Pressure Level ◽  
Slip Parameter ◽  
Electrically Conducting ◽  
Electrically Conducting Fluid ◽  
Slip Effects

This research work is proposed at reporting heat transfer on the peristaltic flow of an electrically conducting fluid in a tapered microvessels under the lubrication theory. The proposed geometry analyzes the blood flow in the heart vessels and maintain the pressure level in the human body. The solutions for the distribution of axial velocity, temperature distribution, pressure gradient and stream function have been obtained analytically. The influences of many evolving parameters on the flow characteristics are revealed and deliberated with the assist of figures. The mathematical outcomes show that the trapped bolus enhances in size with increasing slip parameter but decreases with the increase of Grashof number.

scholarly journals Ballast Flow Characteristics of Discharging Pipeline in Shield Slurry System

2019 ◽  
Vol 9 (24) ◽  
pp. 5402
Author(s):  
Yang Wang ◽  
Yimin Xia ◽  
Xuemeng Xiao ◽  
Huiwang Xu ◽  
Peng Chen ◽  
...  
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Flow Characteristics ◽  
Slurry Flow ◽  
Volumetric Concentration ◽  
Mass Percentage ◽  
Pipe System ◽  
Pipeline Wall ◽  
Slurry Flow Rate

We adopted two-way coupling of discrete and finite elements to examine the non-spherical ballast flow characteristics in a slurry pipe system during a shield project. In the study, we considered the slurry rheological property and the flake shape of the ballast. A ballast size between 17 and 32 mm under different slurry flow rates and ballast volumetric concentration conditions was investigated for determining the law through which the mass flow rate, detained mass percentage, and ballast distribution state are influenced. The results indicate that increasing slurry flow rate and the ballast volumetric concentration increase the mass flow rate; the influence of the latter is stronger. Increases in both in the slurry flow rate and the ballast volumetric concentration can reduce the detained mass percentage in the slurry discharging pipeline, whereas increasing the ballast size has the opposite effect. The increase in both the slurry flow rate and the ballast size changes the ballast motion state. Experiments verified the numerical lifting model of the ballast in the vertical pipeline. The measurements of the actual pipeline wall thickness verified that the simulation results regarding the ballast distribution were accurate.

Studies on flow characteristics of coal–oil–water slurry system

2006 ◽  
Vol 79 (4) ◽  
pp. 217-224 ◽  
Author(s):  
Subrata Kumar Majumder ◽  
Kamal Chandna ◽  
Dhiren Sankar De ◽  
Gautam Kundu
Keyword(s):  
Flow Characteristics ◽  
Water Slurry ◽  
Slurry System ◽  
Oil Water
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